Referring to FIGS. 1 and 2, the conventional water bed includes a body portion having a plurality of tubular members A for receiving water and an air passage B surrounding the body portion. The air passage B is connected with the body portion by high frequency heating. Between the air passage B and the first tubular member A there is a partition B1. Further, there is a partition A1 between every two of the tubular members A. As the water is pressed, the joints B2 and A2 between the upper layer C1 and the lower layer C2 will be directly impacted by water thereby permitting the partitions to be damaged easily.
Therefore, it is an object of the present invention to provide an improvement in the structure of a water bed which can obviate and mitigate the above-mentioned drawbacks.